1. Field of the Invention
The present application relates to a ventilation device, and particularly to a ventilation device mounted on a ceiling which communicates with an outside of a building through a pipe connected to a body for ventilation.
2. Description of the Related Art
A known ventilation device 10 is shown in FIG. 1. The ventilation device 10 comprises a body 11. A fan 12 is disposed in the body 11. Air blown from the fan 12 is discharged through a square air outlet 13 located on a side of the body 11. An adapter 14 is disposed at and connected with the square air outlet 13. The adapter 14 is connected to a pipe communicating with an outside of a building.
FIG. 2 is a schematic view showing structure of a known adapter. The adapter 14 is composed of a square air inlet 141, a circular air outlet 142, and a pipe coupling part 143. An engaging projection 1412 is disposed on an inner wall of the air inlet 141. The adapter 14 is connected with the air outlet 13 of the body 11 through the engaging projection 1412. The adapter 14 is connected with a pipe, which communicates with an outside of a building, through the pipe coupling part 143. A protruding ring 1413 is disposed at an end of the pipe coupling part 143 on an upstream side of the air outlet 13 of the adapter 14, and a plurality of protrusions 1414 are disposed on the protruding ring 1413 to prevent the pipe coupling part 143 of the adapter 14 from being inserted too deeply into the pipe when the pipe is connected with the pipe coupling part 143 of the adapter 14.
The adapter 14 of the prior art ventilation device mentioned above is designed after a diameter of the pipe connected therewith is estimated in advance. In other words, the adapter 14 is suitable only for pipes with the same diameter. In order to satisfy laws and regulations of the regions where the ventilation device is installed, it is difficult to connect the pipe coupling part of the adapter of the ventilation device to a pipe with a different diameter from that of the pipe coupling part.
When a pipe sealing adhesive tape adheres after the pipe coupling part 143 is inserted into the pipe, air possibly leaks from a gap between the adhesive tape and an adhesion surface due to the irregular adhesion surface since the pipe coupling part 143 of the adapter 14 is provided with the protruding ring 1413 and the plurality of the protrusions 1414 to position the pipe.
In addition, when the adapter 14 is fixed, air will leak when an air flow generated by the fan 12 is blown towards the air inlet 13 of the adapter 14 since the body 11 is provided with an opening 111 engaging with the engaging projection 1412 on an inner wall of the square air inlet 13 and a gap exists where the body 11 is connected with the adapter 14 even after the adapter 14 is fixed through the engaging projection 1412.